Evaporator



G. A. VIS

EVAPORATOR Jan. so, 1934.

Filed Jan. 5, 1929 2 'sheets-sheet 1 vV T.

my N BY/ jaa/ Jan. 30, 1934. G. A. vls EVAPRATOR Filed Jan. 1929 2 Sheets-Sheef 2 .J m.. ..2 m., ,/Qd/ 4 m l 4 y M @Q m lf/ *fpm W /Q J @@wwf, llll l, l@ 1 Anfufllllfl [fr LV@ mi JJ A Q W: JJ U Wm ww U y@ U im ATTORNEY.

Patented Jan. 30, 1934 UNITED STATES EVAPORATOR George A. Vis, Detroit, Mich., assignor to Kelvinator Corporation, Detroit, Mich., a corporation of Michigan Application January 5, 1929. Serial'A No. 330,466

15 Claims. (Cl. 62-95) My invention relates to mechanical refrigerating apparatus of the character adapted to be employed within a household refrigerator and it has particular relation to a novel type of evaporator for use in such apparatus for coolingthe refrigerator and for freezing such substances as may be desired.

One object of myinvention is to provide a novel type of evaporator which is particularly efficient because of the intimacy of contact between the refrigerant containing conduits and the objects' placed therein to be frozen.

Another object of my invention consists in providing a new and original type of evaporator which lends itself to strong and durable construction and which is simple and inexpensive to manufacture. i

A further object of my invention is to provide a novel association of evaporator and temperature controlling device whereby the operation of the compressor of the refrigerating system is controlled in accordance with the temperature of the evaporator itself and is substantially unaffected by the temperature ofthe ambient medium.

An additional object of my invention comprises providing a new type of evaporator'which utilizes to great advantage a simple, inexpensive and unusually thin casting as a' support for the cooling coil and also for the objects to be frozen.

Heretofore, various vtypes of evaporators have been employed for cooling refrigerators and for simultaneously freezing water, desserts and the like. Among these types employed have been cast metal evaporators comprising relatively thick walls, with cooling coils disposed about the exterior thereof and adapted to receive objects to be frozen within the walls, the object being to employ the thick metal walls as a reser-v voir or hold over on the theory that such reservoir or hold over serves to prevent sudden uctuations of temperature.` However, experience has shown that the substance usually frozen in evaporators is water, which, because of its high specific heat, imparts a large quantity of heat tov the evaporator; As the walls of these evaporators are comparatively thick, a considerable amount of heat is imparted thereto, and the temperature. thereof lowered, before the temperature responsive device which controls the compressor is actuated. When the compressor is started, the thick walled evaporator acts asv a heat reservoir, and the heat therein must be dissipated before the temperature of the refrigerator can be again lowered and before the freezing of the water' can be resumed.

'By my invention I have eliminated these objections by making the walls of the cast evaporator as thin as practical manufacturing permits, and mounting the electrical thermostat in the casting. When water is placed in my evaporator to be frozen, the intimate metallic contact obtained therewith immediately raises the temperature of the casting, thus starting the compressor. As the expansion coil surrounds the casting, the exterior surface thereof serves to keep the air passing thereover cold and at the same time the majority of the surface'is extracting heat from the cast evaporator, and the compressor continues to operate until the water is frozen, whereupon the temperature of the cast.- ing quickly drops and the motor is stopped.

For a better understanding of my invention reference may now be had to the accompanying drawings of which Fig. 1 is a view, partially in section and partially in front elevation, of anevaporator embodying my invention.

Fig. 2 is a rear elevational view of the strucf ture illustrated in Fig. 1.

Fig. 3 is a fragmentary cross-sectional view of the rear end of the structure shown in Figs. 1 and 2 indicating the method of mounting the electrical thermostat thereon. ,i

Fig. 4 is a fragmentary cross-sectional view of the structure illustrated in Fig. 2, the section being taken along the line IV-IV thereof.

Fig. 5 is a side elevational view of the structure illustrated in Figs. 1 and 2.

Fig. 6 is a top plan view of the structure illustrated in Fig. 5, and

Fig. '7 is a fragmentary cross-sectional View of the structure illustrated in Fig. 2, the section being taken along the line VII-VII thereof.

As illustrated in the drawings, my'invention is embodied. in an evaporator comprising a relatively thin cast iron sleeve 8 which is illustrated as of substantially rectangular cross-section, but which may assume any form from a rectangle to an ellipse, which is provided with a plurality of spaced parallel integral ns 9 on the top and both sides thereof and with a plain at exterior turn, serves to support an additional ice tray or other container of objects to be frozen, as may be desired. The sleeve 8 is provided, adjacent its front end, .with an integral peripheral flange 14, and with -a second similar ange 15, adjacent its rear end.

A cooling coil 16, which is adapted to contain refrigerant, comprises .a long unitary conduit composed of copper or the like, and is wound substantially helically'about the sleeve 8, eachoi` the convolutions 16 being disposed intermediate and in relatively close contact to two adjacent fins 9. As the fins 9 are parallel with the anges 14 and 15, the cooling coil is wound parallel to these anges over the three sides ofthe sleeve 8 which are provided with the ns 9, and on the fourth or fins 9, a quantity of solder, or other good heat l conducting material 17, may be employed to ll the space between the pipe and the ns, as best illustrated in Fig. 7.

At the front end of the sleeve 8 is provided an integral lug or support 18, to which an expansion valve 19, of the type usually employed in refrigerating systems of the dry type, is secured by means of bolts 20, or othersuitable securing devices. A supporting member 21 is associated with the rear end of the sleeve 8 and may be integral therewith or secured thereto, as may be desired, it being necessary only that intimate metallic contact be secured between the member 21 and the sleeve 8. 4The member 2l is provided with an opening 22 through which the end of the cooling coil 16 passes and with a second opening 23 which is adapted to receive a portion 24 of a device 25 which is responsive to changes in temperature and which may, for example, be an electric thermostat. It will be apparent that the cooling fluid or refrigerant enters the cooling coil through the expansion valve 19 at the front end of the evaporator and passes through the successive convolutions to the rear end of the evaporator, at which point the temperature regulating device 25 is disposed,

It will be obvious from this description that this evaporator is adapted to be used in the ordinary household refrigerators so as to cool both the air in the refrigerator by means of its contact with the exterior surface of the sleeve 8 and the coil 16, and that'material may readily be frozen by placing it Within the interior of the sleeve 8, which is in intimate metallic contact with' the cooling coil 16.

This evaporator is intended to be used in conjunction with a compressor and condenser of the ordinary type, the expansion valve being adapted to be connected so as to receive liquid from the condenser and the opposite or outlet end of the coil being connected to the compressor which removes the refrigerant, in the form of gas, therefrom. The thermostat 24 is adapted to be connected so as to control'the operation of the electric motor which operates the compressor, so as to maintain the temperature of the evaporator within certain predetermined limits. The compressor and condenser, as Well as the refrigerant conduit connections thereto and the electrical connections from the thermostat to the motor driving the compressor, are not herein illustrated, as they may be of the usual type and form no part of the present invention.

It will be noted that the thin cast metal sleeve 8 serves both as a support for thecooling coil 16 and for the ice or food trays ll. This casting 8 is purposely made as thin as practical manufacturing limits permit, so that the sleeve will be responsive', without any material time lag, to changes in temperature occasioned either by the operation of the compressor or by the admission to the evaporator of comparatively w substances to be frozen. As the thermostat is in intimate metallic contact with this same sleeve, it will be apparent that changes in temperature of the sleeve will be reected, in a very short time, in the operation of the compressor motor. Likewise, it will be noted that the supporting member 2l, disposed at the rear end ofthe sleeve 8, is intimately associated with the rear end of the cooling coil 16 so that the instant that the sleeve becomes suiiiciently cold to permit refrigerant to reach the endof the coil i6 in liquid form, the thermostat immediately operates to stop the motor driving the compressor, thus eliminating the possibility of the formation of frost on the connection from the ycooling coil to the compressor, which is commonly miown as frosting back.

It will also be apparent that because of the fact that the casting 8 is comparatively thin, the time lag in the freezing of the products placed therein, owing to the necessity of cooling the casting or sleeve as well as food products when any comparatively warm products are placed within the sleeve, is reduced to a Althoughl have illustrated but one form of my invention and have describedin detail but a single application thereof, it will be apparent to those skilled in the art that it is not so limited but that various modifications and changes may be made therein without departing from the spirit of my invention or pended claims.

What I claim is:

l. A refrigerating apparatus including a cooling unit comprising a metallic sleeve member of substantially rectangular cross-section provided with a plurality of transversely extending spaced vintegral iins upon three sides of its exterior surface, and a cooling coil surrounding said sleeve, said coil comprising a single helically wound tube disposed in the space between adjacent ns over. the three nned sides of the sleeve and passing to the next adjacent space between iins while crossing over the fourth side ofsaid sleeve.

2. A refrigerating apparatus including a cooling unit comprising a relatively thin cast metal sleeve provided with a plurality of spaced parallel integral ns upon its exterior surface, and a substantially helically wound cooling coil surrounding said sleeve and having its individual convolutions disposed intermediate said flns'in intimate metallic contact therewith, a metallic supportingl member secured in intimate metallic contact with said sleeve and with the outlet end of said cooling the scope of the apcoil, and means responsive to changes of temperature mounted on said supporting member and adapted to influence the temperature of said cooling coil.`

3. A refrigerating apparatus including a cooling unit comprising a relatively thin cast metal sleeve provided with a plurality of spaced parallel integral ns upon its exterior surface, and a substantiallyl helically wound cooling coil surrounding said sleeve and having its individual convolutions disposed intermediate said fins in intimate metallic contact therewith, a metallic supporting member secured in intimate metallic cony sleeve provided witha plurality of spaced parallel integral fins upon its exterior surface, and a substantially helically wound cooling coil surrounding said sleeve and having its individual' convolutions disposed intermediate said fins in intimate metallic contact therewith, a metallic supporting member secured in intimate metallic contact with said sleeve and provided with an opening therein, and an electrical thermostat disposed'at least partially within said opening and adapted to control the temperature of said cooling coil.

5. A refrigerating apparatus including a cooling unit comprising a relatively thin cast metal sleeve provided with a plurality of spaced parallel integral fins upon its exterior surface, and a substantially helically wound cooling coil surrounding said sleeve and having its individual convolutions disposed intermediate said ns in intimate metallic contact therewith, a refrigerant expansion valve mounted on said sleeve at one end thereof connected to one end of said cooling coil, and a metallic supporting member secured to the opposite end of said sleeve in intimate metallic contact therewith and with the opposite end of said cooling coil and provided with an opening therein, and an electric thermostat disposed at least partially within said opening and adapted to control the temperature of said cooling coil.

6. A refrigerating apparatus including a cooling unit having a cooling coil associatedtherewith, a metallic supporting member secured in intimate metallic contact with said cooling unit and with the outlet end of said cooling coil, and

a temperature responsive device mounted on said metallic supporting member for responding immediately to changes of temperature of either the cooling unit or the end of the cooling coil.

'7. A refrigerating apparatus for refrigerating a cooling medium by inducing its flow thereover, including a cooling unit comprising a metallic sleeve member provided with spaced integral fins upon its exterior surface, a refrigerant circulating cooling coil surrounding said sleeve and exposed to said circulating medium, the individual convolutions of said coil being each disposed between and in thermal contact with two. of said fins, with portions of said convolutions extending substantially in the direction of flow of said me- `dium, and means for controlling the admission of refrigerant to said cooling coil.

8. A refrigerating apparatus for refrigerating a cooling medium by inducing its flow thereover, including a cooling unit comprising a metallic sleeve member provided with `spaced integral transversely extending fins upon its exterior surface, a refrigerant circulating cooling coil surrounding said sleeve and exposed to said circulating medium and having its individual convolutions disposed between and in thermal contact with adjacent iins on'said sleeve, and means for controlling the admission of refrigerant to said cooling coil.

9. A refrigerating apparatus forrefrigerating a cooling medium by inducing its flow thereover, including a cooling unit comprising a relatively thin cast metal sleeve provided with a plurality of spaced,'parallel, integral fins upon its exterior surface, a substantially helically wound refrigerant circulating cooling coil surrounding said sleeve and exposed to said circulating medium and having its individual convolutions disposed intermediate said fins in intimate metallic contact therewith, said sleeve providing a horizontally extray interiorly thereof, and means for controlling the admission of refrigerant to said cooling coil.

t 10. A refrigerating apparatus for refrigerating a cooling medium by inducing its iiow thereover, including a.cooling unit comprising a relatively 4thin cast 4metal sleeve provided with a plurality of spaced, parallel, integral ns upon its exterior surface, a substantially helically wound refrigerant circulating cooling coil surrounding said sleeve and exposed to said circulating medium, and having its individual convolutions disposed intermediate and soldered to said fins, and means for controlling the admission of refrigerant to said cooling coil.

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11. A refrigerating apparatus for regrigerating a cooling medium by inducing its flow thereover, including a cooling unit comprising a relatively thin cast metal sleeve provided with a plurality of spaced, parallel, integral fins upon its exterior surface, a substantially helically wound refrigerant circulating cooling coil surrounding said sleeve and exposed to said circulating medium and having its individual convolutions disposed intermediate and soldered to said ns, said sleeve being adapted to receive an ice tray interiorly thereof, and means for controlling the admission of refrigerant to said cooling coil.

12. A refrigerating apparatus for refrigerating a cooling medium Iby inducing its ow thereover, including a cooling unit comprising a metallic sleeve member provided with a plurality of spaced integral ns upon its exterior surface, each of said'ns lying in a plane perpendicular to the longitudinal axis of the metallic sleeve, a refrigerant circulating cooling coil surrounding said sleeve and exposed to said circulating medium, the individual convolutions of said coil being each disposed between and in thermal contact with two of said fins, and means for controlling the admission of refrigerant to said cooling coil.

13. A refrigerating apparatus for refrigerating air by inducing its flow thereover, including a cooling unit comprising a metallic sleeve member provided with spaced notches upon its exterior surface, and a refrigerant circulating cooling coil having its majorV portion disposed in said notches in thermal contact with said sleeve and a. relatively small portion exposed to the air flowing thereover. L

14. A refrigerating apparatus for refrigerating air and for freezing substances, including a coolcooling coil having its major portion disposed in' said notches in thermal contact with said sleeve and a relatively small portion exposed to the air owing thereover.

15. A refrigerating apparatusfor refrigerating air flowing thereover, including a, cast metallic sleeve member provided with spaced integral fins upon its exterior surface, a refrigerant circulating cooling coil surrounding said sleeve and exposed to said air, the individual convolutions of said coil being disposed between and in thermal contact with at least one of said fins with portions of the convolutions extending substantially in the direction of flow of saidA air, and means for controlling the admission of refrigerant to said cooling coil.

. GEORGE A. vrs, 

